chemistry Unit Chemistry= science of matter (atoms) Atomic Structure

ATOMS or ELEMENTS Atoms: are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms! Matter is anything with mass and volume… so pretty much everything is matter Mass – how many atoms Volume – how much space you take up There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more. Elements : substance consisting of 1 type of atom

History of Atoms… Democritus – Famous teacher who lived in 4th century B.C. Greece (over 2400 years ago) First to suggest the existence of atoms Thought that matter was composed of tiny particles called atoms. Said they were indivisible, indestructible, and fundamental units of matter. He did not experiment to test this Experiments were not done until 2200 years later. About 200 years ago

Dalton’s Atomic Theory: History of Atoms… John Dalton (1766-1844) Dalton was able to perform experiments based off of Democritus ideas and create the atomic theory. Dalton’s Atomic Theory: All matter is made up of subatomic particles called atoms. (smallest unit of matter) Atoms of the same element are identical. Atoms of different elements can physically mix creating a mixture or can chemically combine to form compounds. Chemical reactions occur when atoms bonds are separated, joined, or rearranged. However, atoms of one element are never changed into atoms of another element as a result of chemical reaction.

smallest unit of matter All matter is made up of subatomic particles called atoms. (smallest unit of matter) smallest unit of matter Living things Organ systems Organs Tissues Together they form Cells _____________ __________

2. Atoms of the same element are identical. Hydrogen atom is = to another hydrogen atom 3. Atoms of different elements can physically mix creating a mixture or can chemically combine to form compounds.

Bonds are a result of atoms sharing, taking, or giving up electrons 4. Chemical reactions occur when atoms bonds are separated, joined, or rearranged. However, atoms of one element are never changed into atoms of another element as a result of chemical reaction. Bonds are a result of atoms sharing, taking, or giving up electrons

Vocabulary you need to know… Element- smallest unit of matter. Ex: oxygen, hydrogen Atom- 1 of the smallest units of matter. Ex: 1 oxygen, 1 hydrogen Electrons – Negatively charged subatomic particles, are responsible for all bonding Protons – Positively charged subatomic particles found in the nucleus of the atom Neutrons – Neutrally or no charged subatomic particle. found in the nucleus of the atom

An ATOM… Nucleus = Protons and neutrons Electrons fly around the nucleus in an electron cloud The outer most electrons are called valance electrons – they are responsible for all bonding Mass of the subatomic particles: Neutron = 1 Proton = 0.99862349 Electron = 0.00054386734 The mass of the electron is SOOO tiny we don’t even count it when calculating the mass of an atom Atomic mass = P +N

More Vocabulary Nucleus – The center core of an atom, composed of protons and neutrons. The nucleus is so dense that if it were the size of a pea it would weigh 250 tons.

More Vocabulary Atomic Number – an element is the number of protons in the nucleus of the atom of that element. Atomic number = P Atomic Mass– the total number of protons and neutrons in the nucleus of the atom for all the isotopes of that atom. Atomic Mass = P + N 5 B 10.81

More Vocabulary Isotopes – atoms that have the same number of protons but a different number of neutrons. Ions - Atoms that have the same number of protons and neutron but different number of electron which give them a positive (+) or negative (-) charge When atoms lose an electron it become positive When atoms gain an electron it become negative

Examples of Isotopes Examples of Ions

Not ALL isotopes are radioactive but some IMPORTANT ones are. Carbon-14 Iodide-131 Uranium-238 Plutonium-244

The number of Protons are what make each element unique!! example: only oxygen has 8 protons and all oxygen's have 8 Example: only Boron has 5 protons and all boron's have 5

B 5 10.81 Anatomy of the Box… Boron Atomic Number Symbol Atomic Mass Element Name Atomic Mass B Boron

The atomic number = # protons To get NEUTRONS you simply subtract the number of protons from the rounded ATOMIC MASS IF the atom does not have a charge then… # electrons= # protons If the atom has a charge (ion) then… # Electrons = # of protons (+ OR –) the charge (we will need to flip the charge)

Li 3 6.941 Lithium What is the name of this element? Lithium What is its atomic number? 3 What is its atomic mass? 6.941 How many protons does it have? How many electrons does it have? How many neutrons does it have? 6.94 rounded = 7.0 7.0 -3 = 4

C 6 12.0107 Carbon What is the name of this element? What is its atomic number? What is its atomic mass? How many protons does it have? How many electrons does it have? How many neutrons does it have?

Ag 47 107.8682 Silver What is the name of this element? What is its atomic number? What is its atomic mass? How many protons does it have? How many electrons does it have? How many neutrons does it have?

C 6 +2 12.0107 Carbon What is the name of this element? 6 +2 12.0107 C Carbon What is the name of this element? What is its atomic number? What is its atomic mass? How many protons does it have? How many electrons does it have? How many neutrons does it have?

Ag 47 +4 107.8682 Silver What is the name of this element? 47 +4 107.8682 Ag Silver What is the name of this element? What is its atomic number? What is its atomic mass? How many protons does it have? How many electrons does it have? How many neutrons does it have?

O 8 -2 16.0 oxygen What is the name of this element? 8 -2 16.0 O oxygen What is the name of this element? What is its atomic number? What is its atomic mass? How many protons does it have? How many electrons does it have? How many neutrons does it have?